Vertical tubular bagging machine

ABSTRACT

In order to achieve in a vertical tubular bagging machine ( 1 ) an even foil path precise in location, a foil-removing system is suggested, which provides for a secure introduction of the edges ( 29 ) of a foil web ( 3 ) into a longitudinal sealing device ( 7 ) in order to weld a foil tube ( 5 ) in its transport direction ( 8 ).  
     The foil-removing system has rollers ( 10 ) driven by a drive ( 12 ), which rollers, viewed in transport direction ( 8 ), are provided between the forming shoulder ( 4 ) and the longitudinal sealing device ( 7 ), and an additional foil-removing means ( 19 ) with a drive ( 20 ) and a belt ( 22 ) rotating around two wheels ( 21 ), which belt acts against the foil tube ( 5 ) and thus against the fill pipe ( 6 ), and which acts at a point of the foil tube ( 5 ) where the longitudinal seam ( 9 ) is not. The two drives ( 12, 20 ) are synchronized with one another.

FIELD OF THE INVENTION

The invention relates to a vertical tubular bagging machine. Such machines are used to package products in tubular bags.

BACKGROUND OF THE INVENTION

A vertical tubular bagging machine is known from EP 0 917 946 A1, which has a foil web unwound from a storage roll, a forming shoulder for reshaping the foil web into a foil tube, a vertically aligned fill pipe to receive and fill the foil tube, and a longitudinal sealing device for welding the foil tube parallel to its transport direction. A fin-like longitudinal seam is created during the longitudinal welding of the foil tube. Two rollers provided with a drive clamp the longitudinal seam with their outer surfaces and further transport the entire foil web and the foil tube. Two transverse sealing jaws, which are movable against one another, are used to weld the foil tube transversely with respect to its transport direction and to create top seams and bottom seams on the tubular bags. Each created, filled tubular bag is separated from the foil tube by means of a separating device.

The foil transport occurs in this known tubular bagging machine exclusively by means of rollers, which are pressed against one another. This has the disadvantage that the foil is gripped only linearly, namely at the contact point of the outer surfaces of the rollers, which outer surfaces are pressed against one another. This linear gripping can result in a localized expansion of the foil. In addition, it is disadvantageous regarding the application of a large removing force to move the foil web over the forming shoulder, and for applying the force needed to reshape the flat foil web into a foil tube. In addition, the rollers act below, and thus after, the longitudinal sealing device, so that the guiding function of the rollers in relationship to the not yet welded longitudinal seam is relatively small. The rollers transport first of all the already welded longitudinal seam. A locally precise guiding of the unwelded edges of the foil web into the longitudinal sealing device does not occur.

As an alternative to this type of foil transport, a foil-removing means is known having two belts which each rotate around two wheels, and which act on opposite sides of the fill pipe against the foil tube. Due to the large working surface of the belts, the removing force is applied evenly and thus foil-protectingly onto the foil tube. However, this foil-removing means has the disadvantage that it does not apply any guiding function in the area of the longitudinal seam. An imprecisely guided longitudinal seam can result in an insufficient overlapping of the edges of the foil web and thus in leaky tubular bags.

SUMMARY OF THE INVENTION

The basic purpose of the invention is to further develop a tubular bagging machine of the above-described type so that the edges of the foil web, which edges are to be welded, are guided particularly precisely in location, while the foil transport occurs in a foil-protecting manner.

The purpose is attained in accordance with the characterizing part of claim 1. Accordingly the rollers, which serve to transport the edges of the foil web, are, viewed in transport direction, provided between the forming shoulder and the longitudinal sealing device, and an additional foil-removing means with a drive and a belt rotating around two wheels acts against the foil tube and thus against the fill pipe, namely at a point of the foil tube where the longitudinal seam is not. Moreover, the two drives are synchronized with one another.

The invention has the advantage that the edges of the foil web are guided relatively precisely in location since the rollers lie relatively close to the forming shoulder. Thus the not yet welded edges are guided in the state where they lie safely one on top of the other to the longitudinal sealing device. Thus a leaky longitudinal seam is rather unlikely. A further advantage is that the foil transport occurs in a foil-protecting manner since the foil tube is guided both by the rollers and also by the additional foil-removing means, so that the foil-removing means acts on a relatively large foil surface. The relatively wide belt of the additional foil-removing means particularly contributes to the surface enlargement. A localized expansion of the foil thus does not occur. The surface enlargement is in addition advantageous in order to apply a relatively large removing force to the foil web.

Advantageous developments of the suggested tubular bagging machine are described in the claims 2 to 4.

A particularly large surface for applying a removing force is achieved when according to claim 2 the foil-removing means has two belts each rotating around two wheels, which belts act on opposite sides against the foil tube. In addition, foil protection and a precise foil path are hereby further improved.

Tubular bags with bag-stabilizing side seams can be created, when analogous to claim 3 a fin is formed in the foil tube on a side of the foil tube, which side is opposite the longitudinal seam. A welding device acts against the fin in order to weld the fin. The longitudinal seam and this fin form then the two side seams.

When the fill pipe, with which the bag is filled, is formed of two troughs extending in transport direction, and the spacing between the troughs can be adjusted by means of a spacer (claim 4), then it is possible to widen or narrow down the fill pipe by changing the spacing. Thus it is possible to manufacture tubular bags with different widths.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be discussed in greater detail hereinafter in connection with the figures illustrating one exemplary embodiment. In the drawings:

FIG. 1 is a side view of a vertical tubular bagging machine with two driven rollers, which guide the edges of a foil web into a longitudinal sealing device, and which are provided directly below a forming shoulder, and whereby two driven, rotating belts positioned on opposite sides of a fill tube serve additionally as a foil transport;

FIG. 2 is a side view of the subject matter of FIG. 1 rotated at 90 degrees; and

FIG. 3 is a cross-sectional view along A-A of FIG. 1 of a portion of the subject matter of FIG. 1.

DETAILED DESCRIPTION

A forming shoulder 4 in a vertical tubular bagging machine 1 with a foil web 3 unwound from a storage roll 2 over a guide roller 30 has the purpose to reshape the foil web 3 into a foil tube 5. A vertically aligned fill pipe 6 is provided to receive and fill the foil tube 5. A longitudinal sealing device 7 is used to weld the foil tube 5 parallel to its transport direction 8 in order to create a fin-like longitudinal seam 9. Two rollers 10, which have a drive 12, clamp the longitudinal seam 9 with its outer surfaces 11 in order to move it on. Thus the drive 12 is provided also for the further transport of the foil web 3 and of the foil tube 5. Two cross sealing jaws 13, 14, which can be moved toward one another, are used to weld the foil tube 5 transversely with respect to the transport direction 8 and to create top seams 15 and bottom seams 16 on the tubular bags 17. A created tubular bag 17 is separated from the foil tube 5 by means of a separating device 18. The rollers 10 are, viewed in transport direction 8, provided between the forming shoulder 4 and the longitudinal sealing device 7, thus causing the edges 29 of the foil web 3 to be guided precisely into the longitudinal sealing device 7. An additional foil removing means 19 with a drive 20 is provided for the purpose of applying an additional removing force. This foil-removing means 19 acts against the foil tube 5 and against the fill pipe 6, and thus at a point of the foil tube 5 where the longitudinal seam 9 is not. The two drives 12, 20 are synchronized with one another and have therefore an identical removing speed.

The additional foil-removing means 19 has two belts 22 rotating each around two wheels 21, which belts act on opposite sides against the foil tube 5. The additional foil-removing means acts thus transversely with respect to the direction of the force introduction of the first foil-removing means formed by rollers 10. In addition, the deformable belts 22 rest with each one parallel section flat on the foil tube 5 and thus serve, together with the rollers 10, as an even application of removing forces on the foil tube 5, so that the edges 29 receive in addition a yet more precise direction of movement. A fin 23 is formed in the foil tube 5 on a side of the foil tube 5, which side is opposite the longitudinal seam 9, against which fin acts a welding device 24 in order to weld the fin 23. A foil-removing means gripping the fin 23 is not needed on this fin 23. The foil web 3 has, due to the rollers 10 and the foil-removing means 19, such a good direction stability that the fin 23 is correctly constructed. The fin 23 and the longitudinal seam serve as stabilizing side seams of the tubular bag 17.

The fill pipe 6 is formed of two troughs 25, 26 extending in transport direction 8. The spacing 27 between the troughs 25, 26 can be adjusted by means of a spacer 28 in order to create after a foil exchange tubular bags 17 with a different bag width. 

1. A vertical tubular bagging machine comprising a foil web unwound from a storage roll, a forming shoulder for reshaping the foil web into a foil tube, a vertically aligned fill pipe to receive and fill the foil tube, a longitudinal sealing device for welding the foil tube parallel to a transport direction in order to create a fin-like longitudinal seam, two rollers having a drive, which rollers clamp the longitudinal seam with outer surfaces and further transport them, for which the drive serves the further transport of the foil web and of the foil tube, two transverse sealing jaws that are movable against one another for welding of the foil tube transversely with respect to the transport direction (8) and for creating top seams and bottom seams on tubular bags, and a separating device for separating a created tubular bag from the foil tube, wherein the rollers, viewed in transport direction, are provided between the forming shoulder and the longitudinal sealing device, and that an additional foil-removing means with a drive and a belt rotating around two wheels is provided, which belt acts against the foil tube and thus against the fill pipe, and which acts at a point of the foil tube, where the longitudinal seam is not, whereby the two drives are synchronized.
 2. The tubular bagging machine according to claim 1, wherein the foil-removing means has two belts rotating around each two wheels, which belts act on opposite sides against the foil tube.
 3. The tubular bagging machine according to claim 1, wherein a fin is formed in the foil tube on a side of the foil tube, which side is opposite the longitudinal seam, against which fin acts a welding device in order to weld the fin.
 4. The tubular bagging machine according to claim 1, wherein the fill pipe is formed out of two troughs extending in transport direction, and a spacing between the troughs can be adjusted by means of a spacer.
 5. The tubular bagging machine according to claim 2, wherein a fin is formed in the foil tube on a side of the foil tube, which side is opposite the longitudinal seam, against which fin acts a welding device in order to weld the fin.
 6. The tubular bagging machine according to claim 5, wherein the fill pipe is formed out of two troughs extending in transport direction, and a spacing between the troughs can be adjusted by means of a spacer.
 7. The tubular bagging machine according to claim 3, wherein the fill pipe is formed out of two troughs extending in transport direction, and a spacing between the troughs can be adjusted by means of a spacer.
 8. The tubular bagging machine according to claim 2, wherein the fill pipe is formed out of two troughs extending in transport direction, and a spacing between the troughs can be adjusted by means of a spacer. 